This invention relates to improvements in overhead horizontal pendulum conveyor systems and, in particular, to a pendulum arm therefor which cooperates with a receiver on a carrier frame to lift and transport a vehicle part or other object under assembly along an inclined as well as a horizontal path, such as through surface treatment tanks, where the carrier and part may become buoyant and tend to separate from the pendulum arms.
In the assembly line manufacture of motor vehicles such as automobiles and trucks, it is known to provide an overhead horizontal pendulum conveyor system from which pendulum arms depend, typically in groups of four for supporting the four corners of a rectangular skid frame or carrier. These conventional pendulums hang vertically from the conveyor and have hooks on their lower ends for engaging laterally outwardly projecting arms (connecting arms) extending from the supporting frame of the skid or carrier upon which an object is transported. The connecting arms must extend beyond the maximum width of the carried object to provide clearance for the pendulums. Thus the total width of the carrier must be significantly greater than the width of the object and the supporting frame.
Furthermore, when the carrier and its associated object are disengaged from the pendulum conveyor and transported by other conveyor means, an excessive lateral space is consumed by the width of the carrier frame and its connecting arms, thereby increasing the area that must be clear of obstructions. Additionally, ovens for drying components, for example, must be sized to accommodate the width of the carrier, not just the object. Such carriers also require a large amount of storage space, may be difficult or cumbersome to handle, and the protruding connecting arms may be prone to damage. Once such carrier is shown in U.S. Pat. No. 4,831,962 to Gros.
It is, therefore, the primary object of the present invention to provide a pendulum conveyor in which the width of the carrier associated therewith is minimized.
A corollary to the foregoing object is to provide a pendulum conveyor and associated carrier which are positively interlocked during upward and downward courses.
Another important object of the present invention is to provide an apparatus as aforesaid which automatically locks the pendulum arms to the carrier when the carrier is not substantially horizontal.
Still another important object of the present invention is to provide an apparatus as aforesaid that prevents the carrier and part from becoming separated from the pendulum arms when lowered into a tank of liquid through the use of a receiver on the carrier which is positively interlocked with a mating coupler on a corresponding pendulum arm.
Yet another important object of the present invention is to provide an apparatus as aforesaid which has a carrier which is not prone to damage due to protruding members and minimizes maintenance.
A further important object of the present invention is to provide an apparatus as aforesaid which minimizes the space required for storage.
Another important object of the present invention is to provide an apparatus as aforesaid which accommodates smaller assembly line equipment such as ovens and processing tanks.
Still another important object of the present invention is to provide an apparatus as aforesaid having pendulum arms which extend generally horizontally inwardly to the associated receivers to engage and lock the carrier to the arms.
These and other objects of the invention are achieved by providing a generally L-shaped pendulum arm which depends from an overhead horizontal pendulum conveyor and provides a coupler at the free end of an inwardly extending, horizontal portion of the arm. The coupler is designed to engage a receiver on an associated carrier and automatically interlock when the carrier rotates and assumes an inclined orientation during a downward or upward course of the conveyor. In vehicle part process treatment applications, this eliminates the possibility of the carrier and vehicle part floating off of the pendulum arms when descending into a treatment tank. The carriers may be conveniently handled and stored during nonuse, as the receivers do not add any significant width to the carrier frames.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.